Postsynaptic Targeting and Mobility of Membrane Surface-Localized hASIC1a
- PDF / 4,664,923 Bytes
- 21 Pages / 595.276 x 790.866 pts Page_size
- 43 Downloads / 175 Views
www.neurosci.cn www.springer.com/12264
METHOD
Postsynaptic Targeting and Mobility of Membrane SurfaceLocalized hASIC1a Xing-Lei Song1,2 • Di-Shi Liu1,2 • Min Qiang4 • Qian Li1,2,3 • Ming-Gang Liu1,2,3 • Wei-Guang Li1,2,3 • Xin Qi1,2 • Nan-Jie Xu2,3 • Guang Yang4 • Michael Xi Zhu5 • Tian-Le Xu1,2,3
Received: 28 February 2020 / Accepted: 14 May 2020 Ó The Author(s) 2020
Abstract Acid-sensing ion channels (ASICs), the main H? receptors in the central nervous system, sense extracellular pH fluctuations and mediate cation influx. ASIC1a, the major subunit responsible for acid-activated current, is widely expressed in brain neurons, where it plays pivotal roles in diverse functions including synaptic transmission and plasticity. However, the underlying molecular mechanisms for these functions remain mysterious. Using extracellular epitope tagging and a novel antibody recognizing the hASIC1a ectodomain, we examined the membrane targeting and dynamic trafficking of hASIC1a in cultured cortical neurons. Surface hASIC1a was distributed throughout somata and dendrites, clustered in spine heads, Xing-Lei Song and Di-Shi Liu have contributed equally to this work.
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12264-020-00581-9) contains supplementary material, which is available to authorized users.
and co-localized with postsynaptic markers. By extracellular pHluorin tagging and fluorescence recovery after photobleaching, we detected movement of hASIC1a in synaptic spine heads. Single-particle tracking along with use of the anti-hASIC1a ectodomain antibody revealed long-distance migration and local movement of surface hASIC1a puncta on dendrites. Importantly, enhancing synaptic activity with brain-derived neurotrophic factor accelerated the trafficking and lateral mobility of hASIC1a. With this newly-developed toolbox, our data demonstrate the synaptic location and high dynamics of functionallyrelevant hASIC1a on the surface of excitatory synapses, supporting its involvement in synaptic functions. Keywords ASIC1a Surface labeling Visualization Membrane trafficking Brain-derived neurotrophic factor Synaptic function
& Michael Xi Zhu [email protected]
Introduction
& Tian-Le Xu [email protected]
Fluctuations in extracellular pH occur commonly in the brain during many physiological and pathological processes [1–5]. As major proton sensors, acid-sensing ion channels (ASICs) play several distinct roles in the central and peripheral nervous systems [6–9]. ASICs belong to the degenerin and epithelial Na? channel (DEG/ENaC) superfamily [10]. In rodents, there are three genes encoding five isoforms: ASIC1a, 1b, 2a, 2b, and 3, which can form homo- and heterotrimeric channels in various combinations, with different pH sensitivity, ion selectivity, as well as activation and desensitization kinetics [11–13]. The closely-related isoforms ASIC4 and brain-liver-intestine amiloride-sensitive Na? channel (BLINaC), are unable to produce or modify H?-evoked current
Data Loading...
